Gas Chromatography (GC) is used to resolve a mixture into its various components according to retention profiles of the different molecules passing through a GC column. While the technique can separate mixtures containing hundreds of substances, identifying the molecules that elute from the column is more problematic. To address the need for rapid and sensitive identification of the molecular species present, GC has been integrated with techniques such as mass spectrometry (MS) or Fourier transform infrared (FTIR) spectrometry.
Although Gas chromatography-mass spectrometry (GC-MS) technique is versatile and is employed across many different industries, it suffers from many disadvantages such as compound separation to prevent MS interferences, non-linear calibrations, poor precision and accuracy (requiring constant calibration) and limited dynamic range.
Most GC-MS systems also require user selection of a list of compounds prior to analysis (e.g., approximately 60) and then only report those. Although the MS software can then do a global search and try to identify other peaks, it can seldom perform a quantitative analysis.
Gas Chromatography-Fourier Transform Infrared Spectrometry (GC-FTIR) provides a powerful alternative as an analytical tool. For example, U.S. Pat. No. 9,606,088, to Spartz et al., entitled “Process and System for Rapid Sample Analysis” describes such a system.